Class NumericTokenStream

Expert: this class provides a TokenStream for indexing numeric values that can be used by NumericRangeQuery or NumericRangeFilter.

Note that for simple usage, Int32Field, Int64Field, SingleField or DoubleField is recommended. These fields disable norms and term freqs, as they are not usually needed during searching. If you need to change these settings, you should use this class.

Here's an example usage, for an field: 

    IndexableFieldType fieldType = new IndexableFieldType(TextField.TYPE_NOT_STORED)
    {
        OmitNorms = true,
        IndexOptions = IndexOptions.DOCS_ONLY
    };
    Field field = new Field(name, new NumericTokenStream(precisionStep).SetInt32Value(value), fieldType);
    document.Add(field);

For optimal performance, re-use the TokenStream and Field instance for more than one document: 

    NumericTokenStream stream = new NumericTokenStream(precisionStep);
    IndexableFieldType fieldType = new IndexableFieldType(TextField.TYPE_NOT_STORED)
    {
        OmitNorms = true,
        IndexOptions = IndexOptions.DOCS_ONLY
    };
    Field field = new Field(name, stream, fieldType);
    Document document = new Document();
    document.Add(field);

    for(all documents) 
    {
        stream.SetInt32Value(value)
        writer.AddDocument(document);
    }

this stream is not intended to be used in analyzers; it's more for iterating the different precisions during indexing a specific numeric value.

NOTE: as token streams are only consumed once the document is added to the index, if you index more than one numeric field, use a separate NumericTokenStream instance for each.

See NumericRangeQuery for more details on the precisionStep parameter as well as how numeric fields work under the hood.

@since 2.9

Inheritance
System.Object
AttributeSource
TokenStream
NumericTokenStream
Implements
IDisposable
Inherited Members
Namespace: Lucene.Net.Analysis
Assembly: Lucene.Net.dll
Syntax
public sealed class NumericTokenStream : TokenStream, IDisposable

Constructors

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NumericTokenStream()

Creates a token stream for numeric values using the default Lucene.Net.Analysis.NumericTokenStream.precisionStep PRECISION_STEP_DEFAULT (4). The stream is not yet initialized, before using set a value using the various Set???Value() methods.

Declaration
public NumericTokenStream()
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NumericTokenStream(AttributeSource.AttributeFactory, Int32)

Expert: Creates a token stream for numeric values with the specified precisionStep using the given AttributeSource.AttributeFactory. The stream is not yet initialized, before using set a value using the various Set???Value() methods.

Declaration
public NumericTokenStream(AttributeSource.AttributeFactory factory, int precisionStep)
Parameters
Type Name Description
AttributeSource.AttributeFactory factory
System.Int32 precisionStep
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NumericTokenStream(Int32)

Creates a token stream for numeric values with the specified precisionStep. The stream is not yet initialized, before using set a value using the various Set???Value() methods.

Declaration
public NumericTokenStream(int precisionStep)
Parameters
Type Name Description
System.Int32 precisionStep

Fields

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TOKEN_TYPE_FULL_PREC

The full precision token gets this token type assigned.

Declaration
public const string TOKEN_TYPE_FULL_PREC = null
Field Value
Type Description
System.String
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TOKEN_TYPE_LOWER_PREC

The lower precision tokens gets this token type assigned.

Declaration
public const string TOKEN_TYPE_LOWER_PREC = null
Field Value
Type Description
System.String

Properties

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PrecisionStep

Returns the precision step.

Declaration
public int PrecisionStep { get; }
Property Value
Type Description
System.Int32

Methods

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IncrementToken()

Declaration
public override bool IncrementToken()
Returns
Type Description
System.Boolean
Overrides
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Reset()

Declaration
public override void Reset()
Overrides
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SetDoubleValue(Double)

Initializes the token stream with the supplied value.

Declaration
public NumericTokenStream SetDoubleValue(double value)
Parameters
Type Name Description
System.Double value

the value, for which this TokenStream should enumerate tokens.

Returns
Type Description
NumericTokenStream

this instance, because of this you can use it the following way:

new Field(name, new NumericTokenStream(precisionStep).SetDoubleValue(value))
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SetInt32Value(Int32)

Initializes the token stream with the supplied value.

NOTE: This was setIntValue() in Lucene

Declaration
public NumericTokenStream SetInt32Value(int value)
Parameters
Type Name Description
System.Int32 value

the value, for which this TokenStream should enumerate tokens.

Returns
Type Description
NumericTokenStream

this instance, because of this you can use it the following way:

new Field(name, new NumericTokenStream(precisionStep).SetInt32Value(value))
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SetInt64Value(Int64)

Initializes the token stream with the supplied value.

NOTE: This was setLongValue() in Lucene

Declaration
public NumericTokenStream SetInt64Value(long value)
Parameters
Type Name Description
System.Int64 value

the value, for which this TokenStream should enumerate tokens.

Returns
Type Description
NumericTokenStream

this instance, because of this you can use it the following way:

new Field(name, new NumericTokenStream(precisionStep).SetInt64Value(value))
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SetSingleValue(Single)

Initializes the token stream with the supplied value.

NOTE: This was setFloatValue() in Lucene

Declaration
public NumericTokenStream SetSingleValue(float value)
Parameters
Type Name Description
System.Single value

the value, for which this TokenStream should enumerate tokens.

Returns
Type Description
NumericTokenStream

this instance, because of this you can use it the following way:

new Field(name, new NumericTokenStream(precisionStep).SetSingleValue(value))

Implements

IDisposable